Hi, This patchset continues my work to to add P2PDMA support to the common dma map operations. This allows for creating SGLs that have both P2PDMA and regular pages which is a necessary step to allowing P2PDMA pages in userspace. The earlier RFC[1] and v1[2] postings generated a lot of great feedback. This version adds a bunch more cleanup at the start of the series. I'll probably look to split the earlier patches off and get them merged indpendantly after a round of review with this series as this series has gotten quite long. I'm happy to do a few more passes if anyone has any further feedback or better ideas. This series is based on v5.13-rc1 and a git branch can be found here: https://github.com/sbates130272/linux-p2pmem/ p2pdma_map_ops_v2 Thanks, Logan [1] https://lore.kernel.org/linux-block/20210311233142.7900-1-logang@xxxxxxxxxxxx/ [2] https://lore.kernel.org/linux-block/20210408170123.8788-1-logang@xxxxxxxxxxxx/ Changes sine v1: * Rebased onto v5.13-rc1 * Add some cleanup to the existing P2PDMA code to fix up some naming conventions and documentation as the code has evolved a bit since the names were chosen. (As suggested by John) * Add a patch that adds a warning if a host bridge is not in the whitelist (as suggested by Don) * Change to using dma_map_sgtable() instead of creating a new interface. For this, a couple of .map_sg implementations were changed to return full error codes. (as per Christoph) * Renamed the scatterlist functions to include the term "dma" to indicate that they apply to the DMA side of the sg. (per Jason) * Introduce ib_dma_pci_p2p_dma_supported() helper instead of open coding the check (per Jason) * Numerous minor adjustments and documentation fixes Changes since the RFC: * Added comment and fixed up the pci_get_slot patch. (per Bjorn) * Fixed glaring sg_phys() double offset bug. (per Robin) * Created a new map operation (dma_map_sg_p2pdma()) with a new calling convention instead of modifying the calling convention of dma_map_sg(). (per Robin) * Integrated the two similar pci_p2pdma_dma_map_type() and pci_p2pdma_map_type() functions into one (per Ira) * Reworked some of the logic in the map_sg() implementations into helpers in the p2pdma code. (per Christoph) * Dropped a bunch of unnecessary symbol exports (per Christoph) * Expanded the code in dma_pci_p2pdma_supported() for clarity. (per Ira and Christoph) * Finished off using the new dma_map_sg_p2pdma() call in rdma_rw and removed the old pci_p2pdma_[un]map_sg(). (per Jason) -- Logan Gunthorpe (22): PCI/P2PDMA: Rename upstream_bridge_distance() and rework documentation PCI/P2PDMA: Use a buffer on the stack for collecting the acs list PCI/P2PDMA: Cleanup type for return value of calc_map_type_and_dist() PCI/P2PDMA: Avoid pci_get_slot() which sleeps PCI/P2PDMA: Print a warning if the host bridge is not in the whitelist PCI/P2PDMA: Attempt to set map_type if it has not been set PCI/P2PDMA: Refactor pci_p2pdma_map_type() to take pagemap and device dma-mapping: Allow map_sg() ops to return negative error codes dma-direct: Return appropriate error code from dma_direct_map_sg() iommu: Return full error code from iommu_map_sg[_atomic]() dma-iommu: Return error code from iommu_dma_map_sg() lib/scatterlist: Add flag for indicating P2PDMA segments in an SGL PCI/P2PDMA: Make pci_p2pdma_map_type() non-static PCI/P2PDMA: Introduce helpers for dma_map_sg implementations dma-direct: Support PCI P2PDMA pages in dma-direct map_sg dma-mapping: Add flags to dma_map_ops to indicate PCI P2PDMA support iommu/dma: Support PCI P2PDMA pages in dma-iommu map_sg nvme-pci: Check DMA ops when indicating support for PCI P2PDMA nvme-pci: Convert to using dma_map_sgtable() RDMA/core: Introduce ib_dma_pci_p2p_dma_supported() RDMA/rw: use dma_map_sgtable() PCI/P2PDMA: Remove pci_p2pdma_[un]map_sg() drivers/infiniband/core/rw.c | 75 ++++------ drivers/iommu/dma-iommu.c | 86 +++++++++-- drivers/iommu/iommu.c | 15 +- drivers/nvme/host/core.c | 3 +- drivers/nvme/host/nvme.h | 2 +- drivers/nvme/host/pci.c | 80 +++++----- drivers/nvme/target/rdma.c | 2 +- drivers/pci/Kconfig | 2 +- drivers/pci/p2pdma.c | 273 +++++++++++++++++++---------------- include/linux/dma-map-ops.h | 18 ++- include/linux/dma-mapping.h | 46 +++++- include/linux/iommu.h | 22 +-- include/linux/pci-p2pdma.h | 81 ++++++++--- include/linux/scatterlist.h | 50 ++++++- include/rdma/ib_verbs.h | 30 ++++ kernel/dma/direct.c | 44 +++++- kernel/dma/mapping.c | 31 +++- 17 files changed, 570 insertions(+), 290 deletions(-) base-commit: 6efb943b8616ec53a5e444193dccf1af9ad627b5 -- 2.20.1
